French lippe is from a Germanic source. Transferred sense of "edge or margin of a cup, etc." is from 1590s. Slang sense "saucy talk" is from 1821, probably from move the lip (1570s) "utter even the slightest word (against someone)." To bite (one's) lip "show vexation" is from early 14c. Stiff upper lip as a sign of courage is from 1833. Lip gloss is attested from 1939; lip balm from 1877. Related: Lips.

The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D.Copyright (C) 2007 by HarperCollins Publishers.Cite This Source

Idioms and Phrases with keep a stiff upper lip

keep a stiff upper lip

Show courage in the face of pain or adversity. For example, I know you're upset about losing the game, but keep a stiff upper lip. This expression presumably alludes to the trembling lips that precede bursting into tears.
[ Early 1800s
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